Mobility supporting method of mobile terminal based on prefix binding and mobility supporting system using the method

ABSTRACT

A mobility supporting method and a mobility supporting system using the method are provided. The mobility supporting method includes a first access router for allocating a prefix to a mobile terminal, and registering the allocated prefix in an authentication server when the mobile terminal connects to the first access router. There is also the authentication server for verifying the mobile terminal based on the registered prefix, and reporting a result of the verifying of the mobile terminal to a second access router when the mobile terminal moves to connect to the second access router and the second access router for notifying the reported result of the verifying the mobile terminal to the first access router.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Application No. 60/851,295, filed on Oct. 13, 2006, in theU.S. Patent and Trademark Office, and under 35 U.S.C. §119(a) of KoreanPatent Application No. 10-2006-0116439, filed on Nov. 23, 2006, in theKorean Intellectual Property Office, the entire disclosure of both ofwhich are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wireless network. More particularly,the present invention relates to a mobility supporting method based onprefix binding which can effectively support the mobility of a mobileterminal, and a mobility supporting system using the method.

2. Description of Related Art

Demands for a personal digital assistant (PDA), and a smart phone, amongothers, combining a function of a mobile phone with a function of apersonal computer (PC), will be dramatically increased, and a mobilecommunication network technology and a wireless LAN technology will begreatly developed due to improvements in data processing speed in thenear future. With the development of wireless technology, the number ofwireless terminals capable of supporting mobility will continuallyincrease.

A mobile Internet protocol (IP) of an Internet engineering task force(IETF) has standardized Internet protocol version 6 (IPv6) as a mobilitysupporting standard. The mobile IP is generally divided into a mobileIPv4 for an Internet protocol version 4 (IPv4) network and a mobile IPv6for an IPv6 network, and the mobile IPv4 is considered to beinappropriate for a future communication environment since the mobileIPv4 uses an IPv4 addressing system. Accordingly, the mobile IPv6 isgenerally considered to be a more desirable mobility supporting methodbased on an IP network.

The mobile IPv6 is a protocol which allows a mobile terminal tocommunicate with other terminals without a break of logical connectionseven when the mobile terminal moves to a new link by moving out of itsown home link on an IPv6 Internet.

However, the mobile IPv6 has problems. These problems include the factthat frequent movements of the mobile terminal cannot be adequatelysupported, and a real-time service application cannot be adequatelysupported using only the mobile IPv6 terminal, since the mobile IPv6,i.e. one of mobility supporting methods on a wireless network accordingto a conventional art only supports a general and widespread mobility.

Accordingly, there is a need for an improved system and method for moreeffectively supporting the mobility of a mobile terminal in a wirelessnetwork.

SUMMARY OF THE INVENTION

An aspect of exemplary embodiments of the present invention is toaddress at least the above problems and/or disadvantages and to provideat least the advantages described below. Accordingly, an aspect ofexemplary embodiments of the present invention is to provide a mobilitysupporting method and a mobility supporting system using the methodwhich can effectively support a mobility of a mobile terminal on awireless network by allocating, with an access router, a prefix to eachof the mobile terminals, and supporting the mobility of the mobileterminal based on the allocated prefix.

According to an aspect of exemplary embodiments of the presentinvention, a mobility supporting method is provided. A first accessrouter allocates a prefix to a mobile terminal. The allocated prefix isregistered in an authentication server when the mobile terminal connectsto the first access router. The authentication server verifies themobile terminal based on the registered prefix, and reports a result ofthe verification of the mobile terminal to a second access router whenthe mobile terminal moves to connect to the second access router. Thesecond access router notifies the reported result of the verification ofthe mobile terminal to the first access router.

According to another aspect of exemplary embodiments of the presentinvention, a mobility supporting system is provided that includes anauthentication server, a first access router and a second access router.The authentication server stores registration information to manage theregistration information which corresponds to a mobile terminal in anauthentication prefix list. The first access router allocates a prefixto the mobile terminal and registers the allocated prefix in theauthentication server when the mobile terminal connects to the firstaccess router. The second access router verifies the mobile terminal viathe authentication server and reports the mobile terminal and connectsto a second access router.

Other objects, advantages, and salient features of the invention willbecome apparent to those skilled in the art from the following detaileddescription, which, taken in conjunction with the annexed drawings,discloses exemplary embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other exemplary objects, features, and advantages ofcertain exemplary embodiments of the present invention will be moreapparent from the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a configuration diagram illustrating a mobility supportingsystem of a mobile terminal based on a prefix binding according to anexemplary embodiment of the present invention;

FIG. 2 is a flowchart illustrating a mobility supporting method of themobile terminal based on a prefix binding according to an exemplaryembodiment of the present invention;

FIG. 3 is a flowchart illustrating the registering method of FIG. 2;

FIG. 4 is a flowchart illustrating a reporting method of FIG. 2;

FIG. 5 is a flowchart illustrating a notifying method of FIG. 2; and

FIG. 6 is a flowchart illustrating a transmitting method of FIG. 2.

Throughout the drawings, the same drawing reference numerals will beunderstood to refer to the same elements, features and structures.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The matters defined in the description such as a detailed constructionand elements are provided to assist in a comprehensive understanding ofthe embodiments of the invention. Accordingly, those of ordinary skillin the art will recognize that various changes and modifications of theembodiments described herein can be made without departing from thescope and spirit of the invention. Also, descriptions of well-knownfunctions and constructions are omitted for clarity and conciseness.

It is assumed that a mobile terminal, according to an exemplaryembodiment of the present invention, may be realized into any of amobile communication terminal, a public switched telephone network(PSTN) terminal, a voice over Internet protocol (VoIP), a sessioninitiation protocol (SIP) terminal, a media gateway controller (Megaco)terminal, a personal digital assistant (PDA), a cellular phone, apersonal communication service (PCS) phone, a hand-held personalcomputer (PC), a code division multiple access (CDMA)-2000(1×, 3×)phone, a wideband CDMA (WCDMA) phone, a dual band/dual mode phone, aglobal system for mobile communication (GSM) phone, a mobile broadbandsystem (MBS) phone, or a satellite/terrestrial digital multimediabroadcasting (DMB) phone.

FIG. 1 is a configuration diagram illustrating a mobility supportingsystem of a mobile terminal 160 based on a prefix binding according toan exemplary embodiment of the present invention.

As illustrated in FIG. 1, the mobility supporting system of the mobileterminal 160 based on the prefix binding, according to an exemplaryembodiment of the present invention, may include an authenticationserver 110, a first access router 120, a second access router 130, afirst base station 140, a second base station 150, and the mobileterminal 160.

The mobility supporting system of the mobile terminal 160 based on theprefix binding, according to the exemplary embodiment of the presentinvention, will be described.

The authentication server 110 may store information of the mobileterminal 160 to manage information of the mobile terminal 160, and beconnected to the first access router 120 and the second access router130. According to an exemplary implementation, an identification (ID)which has been allocated with a prefix of the mobile terminal 160, theprefix, and an IP address of an access router which has been used toallocate the prefix, may be stored.

According to an exemplary implementation, the authentication server 110may indicate an authentication, authorization, and accounting (AAA)server capable of performing as a subscriber server, and capable ofperforming functions such as authentication, authorization, andaccounting.

The first access router 120 may allocate the prefix to the mobileterminal 160, register the allocated prefix in the authentication server110, and store the information of the mobile terminal 160 in a firstprefix list to mange the information of the mobile terminal 160, whenthe mobile terminal 160 connects to the first access router 120 via thefirst base station 140. For example, an ID of the mobile terminal 160and information of the prefix may be stored.

When the mobile terminal 160 connects to the second access router 130via the second base station 150, the second access router 130 may verifyinformation of the mobile terminal 160, report that the mobile terminal160 is connected to the first access router 120, receive a data packetwhich was received in the first access router 120, and transmit thereceived data packet to the mobile terminal 160.

According to an exemplary implementation, the second access router 130may also store the information of the mobile terminal 160 in a secondprefix list to manage the information of the mobile terminal 160. Forexample, the ID of the mobile terminal 160 and the information of theprefix may be stored.

Also, the first access router 120 and the second access router 130 mayindicate access routers capable of performing a function of a NetworkMobility (NEMO) home agent.

The mobile terminal 160 may be allocated with the prefix from the firstaccess router 120 when connecting to the first access router 120. Whenthe mobile terminal 160 moves from a service area of the first accessrouter 120 to a service area of the second access router 130, andconnects to the second access router 130, the data packet from thesecond access router 130 may be transmitted to the mobile terminal 160.This data packet would have been received in the first access router120.

FIG. 2 is a flowchart illustrating a mobility supporting method of themobile terminal 160 of FIG. 1 based on a prefix binding according to anexemplary embodiment of the present invention.

As illustrated in FIG. 2, the mobility supporting method of the mobileterminal 160 based on the prefix binding according to an exemplaryembodiment of the present invention may include registering in operationS210, reporting in operation S220, notifying in operation S230, andtransmitting in operation S240.

The mobility supporting method of the mobile terminal 160 based on theprefix binding according to the embodiment of the present invention willbe described in detail.

In step S210, when the mobile terminal 160 connects to the first accessrouter 120, the first access router 120 may allocate a prefix to themobile terminal 160, and register the allocated prefix in theauthentication server 110.

In step S220, when the mobile terminal 160 moves to the second accessrouter 130, the authentication server 110 may verify the mobile terminal160, and report a result of the verifying of the mobile terminal 160 tothe second access router 130.

In step S230, the second access router 130 may notify the reportedresult of the verifying of the mobile terminal 160 to the first accessrouter 120.

Finally, in step S240, when the first access router 120 receives a datapacket, the first access router 120 may transmit the received datapacket to the mobile terminal 160 via the second access router 130. Theabove mentioned operations will be described by referring to FIGS. 3through 6.

FIG. 3 is a flowchart illustrating the registering method of FIG. 2.

As illustrated in FIG. 3, the registering method of FIG. 2 may includetransmitting a signaling message by the mobile terminal 160 in stepS310, registering the mobile terminal 160 in a network entry by theauthentication server 110 in step S320, transmitting the signalingmessage to the mobile terminal 160 by the first access router 120 instep S330, transmitting a registration message to the authenticationserver 110 by the first access router 120 in step S340, and updating anauthentication prefix list by the authentication server 110 in stepS350.

The above mentioned operations will be described in detail.

In step S310, when the mobile terminal 160 connects to the first accessrouter 120, the mobile terminal 160 may transmit the signaling messageto the authentication server 110 via the first access router 120. Instep S320, when the authentication server 110 receives the signalingmessage, the authentication server 110 may register the mobile terminal160 in a network entry based on the received signaling message.

When the registering of the mobile terminal 160 is completed in theauthentication server 110, the first access router 120 may generate aprefix in the mobile terminal 160, and generate a route advertisement(RA) message for allocating the generated prefix to the mobile terminal160. In step S330, the first access router 120 may transmit thegenerated RA message to the mobile terminal 160.

When the registering of the mobile terminal 160 is completed in theauthentication server 110, the first access router 120 may generateregistration information, including the prefix allocated to the mobileterminal 160 by the first access router 120. According to an exemplaryimplementation, the registration information may include an ID of themobile terminal 160, the allocated prefix, and an IP address of thefirst access router 120.

In step S340, the first access router 120 may generate the registrationmessage for registering the generated registration information, and maytransmit the generated registration message to the authentication server110. In step S350, when the authentication server 110 receives theregistration message, the authentication server 110 may update thepreviously stored prefix list based on the registration information,included in the registration message.

FIG. 4 is a flowchart illustrating the reporting method of FIG. 2.

As illustrated in FIG. 4, the reporting method of FIG. 2 may includetransmitting a signaling message to the authentication server 110 by themobile terminal 160 in step S410, verifying the mobile terminal by theauthentication server 110 in step S420, and transmitting a reportingmessage to the second access router 130 by the authentication server 110in step S430.

The reporting method of FIG. 2 will now be described in detail.

In step S410, when the mobile terminal 160 moves from a service area ofthe first access router 120 to a service area of the second accessrouter 130 and connects to the second access router 120, the mobileterminal 160 may transmit the signaling message to the authenticationserver 110 via the second access router 130.

In step S420, when the authentication server 110 receives the signalingmessage, the authentication server 110 may verify whether registrationinformation corresponding to the mobile terminal 160 exists in apreviously stored prefix list.

In step S430, when the registration information exists in the previouslystored prefix list, the authentication server 110 may generate areporting message including the registration information, and transmitthe generated reporting message to the second access router 130.

FIG. 5 is a flowchart illustrating the notifying method of FIG. 2.

As illustrated in FIG. 5, the notifying method of FIG. 2 may includetransmitting a binding update message to the first access router 120 bythe second access router 130 in step S510, transmitting a bindingacknowledge message to the second access router 130 by the first accessrouter 120 in step S520, and transmitting an RA message to the mobileterminal 160 by the second access router 130 in step S530.

The notifying method of FIG. 2 will be described in detail.

In step S510, when the second access router 130 receives the reportingmessage as a result of the reporting of the verifying of the mobileterminal, the second access router 130 may generate a binding updatemessage based on the registration information, included in the reportingmessage, and transmit the generated binding update message to the firstaccess router 120.

In step S520, when the first access router 120 receives the bindingupdate message, the first access router 120 may generate a bindingacknowledge message, and transmit the generated binding acknowledgemessage to the second access router 130.

In step S530, when the second access router 130 receives the bindingacknowledge message, the second access router 130 may update apreviously stored second prefix list, generate an RA message forreporting a use of a prefix allocated by the first access router 120,and transmit the generated RA message to the mobile terminal 160.

FIG. 6 is a flowchart illustrating the transmitting method of FIG. 2.

As illustrated in FIG. 6, the transmitting method of FIG. 2 may includereceiving a data packet by the first access router 120 in step S610,relaying the data packet to the second access router by the first accessrouter in step S620, and transmitting the data packet to the mobileterminal 160 by the second access router 130 in step S630.

The transmitting method of FIG. 2 will now be described in detail.

When the first access router 120 receives the data packet having an IPaddress of the mobile terminal 160 as a destination address in operationS610, the first access router 120 may verify a previously stored firstprefix list, and relay the received data packet to the second accessrouter 130 in step S620.

In step S630, when the second access router 130 receives the data packetfrom the first access router 120, the second access router 130 mayverify a previously stored second prefix list, and transmit the receiveddata packet to the mobile terminal 160.

The mobility supporting method, according to an exemplary embodiment ofthe present invention, may be recorded in computer-readable mediaincluding program instructions to implement various operations embodiedby a computer. The media may also include, alone or in combination withthe program instructions, data files, data structures, and the like.Examples of computer-readable media include magnetic media such as harddisks, floppy disks, magnetic tape, optical media such as CD ROM disksand DVD, magneto-optical media such as optical disks and hardwaredevices that are specially configured to store and perform programinstructions, such as read-only memory (ROM), random access memory(RAM), and flash memory, among others. The media may also be atransmission medium such as optical or metallic lines, and wave guides,among others, including carrier wave transmitting signals specifying theprogram instructions, and data structures, among others. Examples ofprogram instructions include both machine code, such as that produced bya compiler, and files containing higher level code that may be executedby the computer using an interpreter. The described hardware devices maybe configured to function as one or more software modules in order toperform the operations of the above-described embodiments of the presentinvention.

As described above, a mobility supporting method and mobility supportingsystem using the method according to an exemplary embodiment of thepresent invention can effectively support a mobility of a mobileterminal on a wireless network by allocating, with an access router, aprefix to each of the mobile terminals, and supporting the mobility ofthe mobile terminal based on the allocated prefix.

While the present invention has shown and described with reference tocertain exemplary embodiments thereof, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention asdefined by the appended claims and their equivalents.

1. A mobility supporting method, the method comprising: allocating aprefix to a mobile terminal using a first access router, and registeringthe allocated prefix in an authentication server when the mobileterminal connects to the first access router; verifying the mobileterminal based on the registered prefix using the authentication server,and reporting a result of the verifying of the mobile terminal to asecond access router when the mobile terminal moves to connect to thesecond access router; and notifying the reported result of the verifiedmobile terminal to the first access router using the second accessrouter.
 2. The method of claim 1, wherein the authentication servercomprises an authentication, authorization, and accounting (AAA) servercapable of performing functions of authentication, authorization, andaccounting.
 3. The method of claim 1, wherein the first and secondaccess routers are access routers capable of performing a function of aNetwork Mobility (NEMO) home agent.
 4. The method of claim 1, whereinthe registering of the allocated prefix in the authentication servercomprises: transmitting a signaling message to the authentication servervia the first access router by the mobile terminal, when the mobileterminal connects to the first access router; registering, by theauthentication server, the mobile terminal in a network entry when theauthentication server receives the signaling message; transmitting, bythe first access router, a route advertisement (RA) message to allocatethe prefix to the mobile terminal when the registering of the mobileterminal in the network entry is completed; transmitting, by the firstaccess router, a registration message to register registrationinformation, comprising the allocated prefix, to the authenticationserver when the transmitting of the RA message is completed; andupdating, by the authentication server, a previously stored prefix listbased on the registration information, comprised in the registrationmessage when the authentication server receives the registrationmessage.
 5. The method of claim 4, wherein the registration informationcomprises an identification (ID), that has been allocated with theprefix, of the mobile terminal, the allocated prefix, and an IP address,that has been used to allocate the prefix, of the first access router.6. The method of claim 1, wherein the reporting of the result of theverifying of the mobile terminal to the second access router comprises:transmitting, by the mobile terminal, the signaling message to theauthentication server via the second access router when the mobileterminal moves to connect to the second access router; verifying, by theauthentication server, whether the registration informationcorresponding to the mobile terminal exists in the stored prefix listwhen the authentication server receives the signaling message; andgenerating, by the authentication server, a reporting message comprisingthe registration information, and transmitting the generated reportingmessage to the second access router when the registration informationexists.
 7. The method of claim 1, wherein the reporting of the result ofthe verifying of the mobile terminal to the second access routercomprises: generating, by the first access router, a binding updatemessage based on the registration information, comprised in thereporting message, and transmitting the generated binding update messageto the first access router when the second access router receives thereporting message as the reported result of the verifying of the mobileterminal; verifying, by the first access router, the previously storedfirst prefix list, generating a binding acknowledge message to permitthe binding list, and transmitting the generated binding acknowledgemessage to the second access router when the first access routerreceives the binding update message; and updating, by the second accessrouter, a second prefix list that has been previously stored, andtransmitting the RA message for reporting a use of the allocated prefixthe mobile terminal when the second access router receives the bindingacknowledge message.
 8. The method of claim 1, further comprising:transmitting, by the first access router, a data packet to the secondaccess router when the first access router receives the data packetcomprising an IP address of the mobile terminal as the destinationaddress; and receiving, by the second access router, the data packet andtransmitting the received data packet to the mobile terminal.
 9. Acomputer-readable storage medium storing a program for implementing amobility supporting method, the method comprising: allocating a prefixto a mobile terminal using a first access router, and registering theallocated prefix in an authentication server when the mobile terminalconnects to the first access router; verifying the mobile terminal basedon the registered prefix using the authentication server, and reportinga result of the verifying of the mobile terminal to a second accessrouter when the mobile terminal moves to connect to the second accessrouter; and notifying the reported result of the verified mobileterminal to the first access router using the second access router. 10.A mobility supporting system comprising: an authentication server forstoring registration information to manage the registration information,wherein the registration information corresponding to a mobile terminalis in an authentication prefix list; a first access router forallocating a prefix to the mobile terminal, and for registering theallocated prefix in the authentication server when the mobile terminalconnects to the first access router; and a second access router forverifying the mobile terminal via the authentication server, and forreporting the mobile terminal's connection to the second access router.11. The system of claim 10, wherein the authentication server comprisesan authentication, authorization, and accounting (AAA) server capable ofperforming functions of authentication, authorization, and accounting.12. The system of claim 10, wherein the first and second access routersare access routers capable of performing a function of a NetworkMobility (NEMO) home agent.
 13. The system of claim 10, wherein thefirst access router transmits a route advertisement (RA) message toallocate the prefix to the mobile terminal when the mobile terminalconnects to the first access router; and transmits a registrationmessage to register registration information, comprising the allocatedprefix, to the authentication server when the transmitting of the RAmessage is completed.
 14. The system of claim 13, wherein theauthentication server updates the authentication prefix list based onthe registration information, comprised in the registration message,when the registration message is received.
 15. The system of claim 13,wherein the registration information comprises an identification (ID),that has been allocated with the prefix, of the mobile terminal, theallocated prefix, and an IP address, that has been used to allocate theprefix of the first access router.
 16. The system of claim 10, whereinthe authentication server verifies whether registration informationcorresponding to the mobile terminal exists in the authentication prefixlist when the mobile terminal connects to the second access router;generates a reporting message comprising the registration information,and transmits the generated reporting message to the second accessrouter when the registration information exists.
 17. The system of claim16, wherein the second access router generates a binding update messagebased on the registration information comprised in the reportingmessage, and transmits the generated binding update message to the firstaccess router when the reporting message is received from theauthentication server, and updates a previously stored second prefixlist, and transmits an RA message for reporting a use of the allocatedprefix to the mobile terminal when a binding acknowledge message isreceived in response to the binding update message from the secondaccess router.
 18. The system of claim 17, wherein, when the bindingupdate message is received, the first access router verifies thepreviously stored first prefix list, generates the binding acknowledgemessage for permitting the binding, and transmits the generated bindingacknowledge message to the second access router.
 19. The system of claim10, wherein, when the first access router receives a data packetcomprising an IP address of the mobile terminal as the destinationaddress, the first access router transmits the data packet to the secondaccess router, and the second access router receives the data packet andtransmits the received data packet to the mobile terminal.
 20. Thesystem of claim 10, wherein the mobile terminal comprises any of amobile communication terminal, a public switched telephone network(PSTN) terminal, a voice over Internet protocol (VoIP) terminal, asession initiation protocol (SIP) terminal, a media gateway control(Megaco) terminal, a personal digital assistant (PDA), a mobile phone, apersonal communication service (PCS) phone, a hand-held personalcomputer (PC), a Code Division Multiple Access (CDMA)-2000 (1×, 3×)phone, a Wideband CDMA phone, a dual band/dual mode phone, a GlobalSystem for Mobile Communications (GSM) phone, a mobile broadband system(MBS) phone, and a satellite/terrestrial Digital Multimedia Broadcasting(DMB) phone.